Support is requested for the first Gordon Research Conference (GAC) meeting on Photosensory Receptors and Signal Transduction to be held May 19-24, 2002 at the GRC site in Barga, Italy. This new conference was developed and approved in view of the recent breakthrough discoveries of new photosensory receptors and current rapid progress on their activation and signaling mechanisms. The focus is on molecular mechanisms of receptor phototransduction and brings together investigators of structure/function of microbial, plant, and animal photoreceptors. The meeting will provide a very much-needed opportunity to exchange information and ideas and for investigators to become aware of the diverse and incisive molecular tools available in this fast-moving area of research. We expect the conference will stimulate exciting discussion of emerging insights, general principles, and the most engaging mysteries on the cutting edge of photosensory signal transduction.